CYATHOCRINIDAE 
135 
Parisocrinus siluricus new species 
Plate 31, figs. 8, 8a 
Parisocrinus Wachsmuth and Springer, Rev. Pal., i, 1879, P- uSi ibid., 3, 1886, p. 221. — Springer, New 
Amer. Foss. Crin., Mem. M. C. Z. Harvard, 1911, p. iS/. — Zittel-Eastman, Textb. Pal., 2d ed., 1913, 
p. 218. 
This primarily Lower Carboniferous type, occurring sparsely in the De- 
vonian, must now be moved a step further back in the geological scale as the 
result of the discovery of the fine species here illustrated. The genus has been 
described as a Cyathocrinid with Poteriocrinid anal side — that is, it has curved 
radial facets only part the width of the radials, and non-pinnulate arms, com- 
bined with a large radianal ; as a further Cyathocrinid character it has the anal 
opening at the distal end of a large tube. ' These characters are strongly empha- 
sized in the present species. It has a smooth, expanding turbinate calyx with 
5 large IBB, large RR with facets directed upward; rather stout arms bifur- 
cating twice or oftener, with fairly long brachials. The tube is large in propor- 
tion to the calyx, as usual in the genus, and is heavily plated to the end. RA is 
only partly shown in figure 15a, but it is nearly as large as .r. Column large, 
composed of alternating columnals. 
Horizon and locality. Laurel limestone; St. Paul, Indiana. 
Gissocrinus Angelin 
Plate 32 
Gissocrinus Angelin, Icon. Crin. Suecc., 1878, p. 10. — Wachsmuth and Springer, Rev. Pah, i, p. 89. — 
Bather, Crin. Goth, 1893, p. 152; Treatise on Zooh, 3, 1900, p. 175. — Zittel-Eastman, Textb. Pah, 2d 
ed., 1913, p. 220. 
Similar to Cyathocrimis, but with less than 5 IBB, and a tendency to greater 
surface sculpture and variation in arms. 
Genotype. Gissocrinus typus Bather. 
Distribution. Silurian ; Gotland, England, America. 
This genus, one of the most prominent Inadunate crinoids of Gotland and England, has 
not hitherto been known in America. It is now represented in our Silurian fauna by several 
species, one of which presents characters wholly novel. Nine species are recognized from 
Gotland, two of which are also well known in England, and one is common at Dudley only. 
The Gotland species are all fully described in Bather’s work of 1893, above cited. 
Gissocrinus lyoni new species 
Plate 32, figs, i, la 
A rather massive species, of the type of the English species G. goniadactylus 
Phillips {Cyathocrinites goniadactylus, in Murchison’s Silurian System, 1839, 
p. 671, pi. 17, fig. i). IBB 3. Cup rather low, broadly spreading. Arms stout. 
